@misc{indiciae12c1b9924b7e,
  title = {Corals as guides to divisions of the Pennsylvanian system in the Western Interior region},
  author = {W.J. Sando},
  year = {1984},
  doi = {10.3133/ofr8479},
  url = {https://pubs.usgs.gov/publication/ofr8479},
  note = {Source identifier: ofr8479}
}